1. Field of the Invention
This invention is directed to air flow and filtration systems, in general, and to a headgear structure which is worn by an individual in an environment wherein control of filtered air is required, in particular.
2. Prior Art
There are several types of air flow and/or filtration systems which are known in the art. Several types of such systems are currently available on the market for use in surgical or "clean room" environments.
Some of the existing systems have a bulbous or hemispherical, transparent viewing screen which creates substantial distortion for the wearer. In the case of surgical procedures, especially very delicate surgical procedures, any type of visual distortion is undesirable. Such distortion can create a situation with significant safety problems. Moreover, this distortion can create substantial fatigue in the surgeon because of the additional intensity required to compensate for the distortion during the surgical procedures.
Similarly, in "clean room" situations, such distortion can be a problem in terms of fatigue, inaccurate or imprecise procedures and the like. This can result in the fabrication of defective products or the like.
Furthermore, many of the systems known in the art tend to produce an uneven airflow therethrough. This has the effect of creating drafts in some locations and little or no airflow in other locations within the system. This situation can sometimes result in the transparent screen or shield becoming fogged due to condensation of expired air generated by the surgeon or technician during the procedures involved.
Also, in some systems the transparent shield is separated from the protective hood. This arrangement permits air to flow around the shield. However, it also permits contamination to pass around the shield, as well. Thus, contaminated air or undesirable substances can come into contact with the wearer. Conversely, the wearer can provide contaminated air, or the like, to the work space.
Some of the existing systems include hoods, gowns, filters and the like. In some instances, the filters are built into the helmet structure and produce a rather clumsy, cumbersome headgear unit. Known units frequently include external sources such as gas cylinders, air lines or the like which are connected to the helmet structure by tubes, hoses or the like. Of course, the hose-connected systems tend to become cumbersome and restrictive in the movements and flexibility of the wearer during a procedure.